std::iswdigit
From cppreference.com
Defined in header <cwctype>
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int iswdigit( wint_t ch ); |
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Checks if the given wide character corresponds (if narrowed) to one of the ten decimal digit characters 0123456789
.
Parameters
ch | - | wide character |
Return value
Non-zero value if the wide character is an numeric character, zero otherwise.
Notes
std::iswdigit
and std::iswxdigit are the only standard wide character classification functions that are not affected by the currently installed C locale.
Example
Some locales offer additional character classes that detect non-ASCII digits
Run this code
#include <iostream> #include <cwctype> #include <clocale> void test(wchar_t a3, wchar_t u3, wchar_t j3) { std::wcout << std::boolalpha << " '" << a3 << "' '" << u3 << "' '" << j3 << "'\n" << "iswdigit " << (bool)std::iswdigit(a3) << " " << (bool)std::iswdigit(u3) << " " << (bool)std::iswdigit(j3) << '\n' << "jdigit: " << (bool)std::iswctype(a3, std::wctype("jdigit")) << ' ' << (bool)std::iswctype(u3, std::wctype("jdigit")) << ' ' << (bool)std::iswctype(j3, std::wctype("jdigit")) << '\n'; } int main() { wchar_t a3 = L'3'; // the ASCII digit 3 wchar_t u3 = L'三'; // the CJK numeral 3 wchar_t j3 = L'3'; // the fullwidth digit 3 std::setlocale(LC_ALL, "en_US.utf8"); std::wcout << "In american locale:\n"; test(a3, u3, j3); std::wcout << "\nIn japanese locale:\n"; std::setlocale(LC_ALL, "ja_JP.utf8"); test(a3, u3, j3); }
Output:
In american locale: '3' '三' '3' iswdigit true false false jdigit: false false false In japanese locale: '3' '三' '3' iswdigit true false false jdigit: false false true
See also
checks if a character is classified as a digit by a locale (function template) | |
checks if a character is a digit (function) | |
C documentation for iswdigit
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ASCII values (hex) |
characters |
isdigit |
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0 - 8 | 0x00-0x08
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control codes (NUL , etc.)
|
≠0
|
0
|
0
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0
|
0
|
0
|
0
|
0
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0
|
0
|
0
|
0
|
9 | 0x09
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tab (\t )
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≠0
|
0
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≠0
|
≠0
|
0
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0
|
0
|
0
|
0
|
0
|
0
|
0
|
10 - 13 | 0x0A-0x0D
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whitespaces (\n ,\v ,\f ,\r )
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≠0
|
0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
14 - 31 | 0x0E-0x1F
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control codes | ≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
0
|
32 | 0x20
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space | 0
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≠0
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≠0
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≠0
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0
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0
|
0
|
0
|
0
|
0
|
0
|
0
|
33 - 47 | 0x21-0x2F
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!"#$%&'()*+,-./
|
0
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≠0
|
0
|
0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
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48 - 57 | 0x30-0x39
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0123456789
|
0
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≠0
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0
|
0
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≠0
|
0
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≠0
|
0
|
0
|
0
|
≠0
|
≠0
|
58 - 64 | 0x3a-0x40
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:;<=>?@
|
0
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≠0
|
0
|
0
|
≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
|
65 - 70 | 0x41-0x46
|
ABCDEF
|
0
|
≠0
|
0
|
0
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≠0
|
0
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≠0
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≠0
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≠0
|
0
|
0
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≠0
|
71 - 90 | 0x47-0x5A
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GHIJKLMNOPQRSTUVWXYZ
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0
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≠0
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0
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0
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≠0
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0
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≠0
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≠0
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≠0
|
0
|
0
|
0
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91 - 96 | 0x5B-0x60
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[\]^_`
|
0
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≠0
|
0
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0
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≠0
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≠0
|
0
|
0
|
0
|
0
|
0
|
0
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97 -102 | 0x61-0x66
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abcdef
|
0
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≠0
|
0
|
0
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≠0
|
0
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≠0
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≠0
|
0
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≠0
|
0
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≠0
|
103-122 | 0x67-0x7A
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ghijklmnopqrstuvwxyz
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0
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≠0
|
0
|
0
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≠0
|
0
|
≠0
|
≠0
|
0
|
≠0
|
0
|
0
|
123-126 | 0x7B-0x7E
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{|}~
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0
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≠0
|
0
|
0
|
≠0
|
≠0
|
0
|
0
|
0
|
0
|
0
|
0
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127 | 0x7F
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backspace character (DEL )
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≠0
|
0
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0
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0
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0
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0
|
0
|
0
|
0
|
0
|
0
|
0
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